Spark plug



June 19, 1934. Ml O'MARRA 1,963,801

SPARK PLUG Filed March 14), 1935 Z3 73 mlllligu Z4 T.) 191. .ZZ Z ZZ 7'l 3J) if 54 33 37 55755 5 t. D i

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ATTORNEY 'provision of means for regulating the flow Patented June 19,1934 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to spark plugs for internal combustion enginesand has for the primary object, the provision of a device of the abovestated character which will thoroughly and completely ignite the entireamount of fuel under compression in the cylinder of an engine toincrease the power of the latter to a maximum and permit an auxiliarysupply of air to be admitted to the fuel of the engine through the sparkplug so as to reduce the consumption of fuel to a maximum.

Another object is the provision of an ignition chamber in the body of aspark plug and in communication with the explosion chamber of the engineby a series of ports and confining within the ignition chamber theelectrodes so that the compressed fuel of the engine may enter theignition chamber and be ignited by a series of electrical arcs producedby theelectrodes and readily escape through the ports over a wide areaof the explosion chamber to ignite and burn completely the entire amountof fuel in the explosion chamber.

A further object of this invention is the provision of one of theelectrodes of the spark plug providing a valve to admit air through themark plug to the explosion chamber of the engine during the suctionstroke of the latter.

A still further object of this invention is the of air through the sparkplug to the explosion chamber of the engine.

With these and other objects in view this invention consists in certainnovel features of construction, combination and arrangement of parts tobe hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had tothe following description and accompanying drawing, in which Figure l isa fragmentary vertical sectional view illustrating an `engine with thespark plug applied thereto and constructed in accordance with myinvention.

Figure 2 is a vertical sectional view illustrating the spark plug.

Figure 3 is a sectional view taken on the line 3-3.of Figure 2.

Figure 41s a sectional view taken on the line 4--4 of Figure- 2.

Figure 5 is a sectional view taken 5-5 of Figure 2.

Figure 8 is an end view illustrating the series of ports or passages forestablishing communication between the ignition chamber and the body onthe line of the spark plug and the explosion chamber of the engine.

Referring in detail to the drawing,'the numeral 1 indicates the body ofthe spark plug reduced and screw threaded, as shown at 2, for threadedconnection with the spark plug opening 3 of the engine 4, the latterhaving the usual explosion chamber 5. The extension 2 of the body 1 isclosed by a wall 6 having formed therein an intermediate port or passage'I and a series of radially 65 extending ports or passages 8. The portsor passages 8 establish communication between the interior of theextension 2 of the body 1 and the venting accumulation of carbon thereonand to permit a better distribution of the burning fuel from theinterior of the extension to the explosion chamber 5 so that the burningfuel may 75 cover approximately the entire area of the explosionchamber.

Formed within the body l and the extension 2 thereof are annularshoulders 10 and 11, the shoulder 10 forming a seat for an insulator 1280 while the shoulder 11 provides a seat for an electrode 13. Theinsulator l2 extends out of the body l and is retained in engagementwith the shoulder 10 by an externally threaded sleeve 14 having threadedconnection with the body and bearing` upon a shoulder 15 of theinsulator. Gaskets 16 and 17 are interposed between the insulator andthe shoulder 10 and the sleeve 14 and the shoulder 15 to establishleak-proof connection between the insulator and the body. The insulatoris provided with a bore in which is mounted a metallic sleeve 18, theinner end oi' which is enlarged to form a valve seat 19 and a shoulder20 to abut a shoulder 2l formed in the walls of the bore of theinsulator. The sleeve 18 extends exteriorly of the insulator and isexternally threaded. A cap 22 is threaded to the sleeve 18 and carries abinding post 23 on which is threaded a clamping ut 24 to permit anelectrical conductor to be firmly secured to the cap.

Between the inner end ot the insulator 12 and the end wall 6 is anignition chamber 25, located within the extension 2 of the body 1 withthe electrode 13 positioned intermediate the ends of the chamber 25. Theelectrode 13 is in the form 105 of a metallic disc 26 resting on theshoulder 11 and provided with a centrally located opening 2'1.

A plurality of tapering prongs 28 are located within the opening 2'1 andform an integral part o! the disc 26 having their free ends spaced about110 fuel provides an electrode 29 which extends through the opening 27to provide a series of spark gaps between the electrodes. The electrode29 is detachably secured to a valve 30 adapted to have engagement withthe seat 19 of the sleeve 18. A plurality of guides 31 are carried bythe valve and extend into the bore of the sleeve or the enlarged endthereof to guide the movement of the valve towards and from the seatduring the operation of the device. A tension means 34 normally retainsthe valve 30 in engagement with the seat 19 and consists of a rod 32secured to the valve and having a portion thereof formed into acontractile spring 34 formed integrally with an anchoring cap 25interposed between the end of the sleeve 18 and the cap 22. The sleeve18 is provided with oppositely arranged openings 36 alining withopenings 37 in the cap 22 to place the ignition chamber 25 incommunication with the atmosphere when the valve 30 is unseated. Byadjusting the cap 22 on the sleeve the flow of air into the ignitionchamber may be regulated and the cap may be locked in any of itsadjusted positions on the sleeve by a lock nut 38 threaded to the sleeveand bearing against the cap.

An insulating shield 39 is wound on the sleeve 18 and bears against theinsulator and is of substantially cup-shape with the walls corrugatedfor the purpose of preventing electricity from the conductor connectedto the cap jumping to any of the metallic parts of the spark plug. I'heshield 39 is held in engagement with the insulator l2 by a nut threadedto the tube.

The electrode 13 is held against the shoulder 11 by a sleeve 40interposed between said electrode and the inner end of the insulator.

By reference to Figure 2 it will be seen that it is a simple matter toremove the electrodes 13 and 39 by simply removing the insulator 12 fromthe body l and the sleeve 40 and this permits the electrodes to bereadily replaced when worn by new electrodes, consequently rendering thespark plug fit for further use and thereby permit the Successfulemployment or use of the spark plug over a long period of time.

In operation, during the compression stroke of the engine to compressthe fuel within the explosion chamber, some of the fuel enters theignition chamber 25 and when the electricity arcs between the electrodesthis fuel is ignited and escapes through the ports 7 and 8 over a largearea of the explosion chamber 5, thoroughly and completely igniting allof the fuel so as to produce maximum power to the engine. The fuelsurging into the ignition chamber and passing therefrom in a burningcondition prevents the accumulation of carbon between the electrodesthereby reducing the possibility of the electrodes becoming foul to aminimum. During the suction stroke of the engine, the valve 30 unseatsadmitting air through the spark plug to the explosion chamber for mixingwith the incoming fuel. This additional supply of air to the explosionchamber and the complete burning of the maximum power with a minimumconsumption of fuel. It is to be understood that the valve seatsautomatically during the compression stroke of the engine through theaid of the tension means 34.

While I have shown and described the preferred embodiment of myinvention, it will be understood that minor changes in constructioncombination and arrangement of parts may be made without departing fromthe spirit and scope of my invention, as claimed.

Having described the invention, I claim:

l. A spark plug comprising a body having an ignition chamber and aplurality of radially arranged passages to establish communicationbetween the ignition chamber and the explosion chamber of an engine, aninsulator carried by ihe body, a metallic tube carried by the insulatorto the atmosphere. the body and the air through the tube to the ignitionchamber.

2. A spark plug comprising a body having one end closed, an insulatormounted in the body and forming between itself and the closed end of thebody an ignition chamber, said closed end of the body having a series ofangularly related passages to communicate the ignition chamber withengine, an electrode communication with the atmosphere and its oppositeend formed to provide a valve seat in the ignition chamber, a valve toengage said seat and having the second-named electrode detachablyconnected thereto, spring means between the tube and the valve tourgethe latter in engagement with the seat, and means for connecting anelectrical conductor to the tube.

3. A spark plug comprising a body having one end closed, an insulatormounted in the body and forming between itself and the closed end of thebody an ignition chamber, said closed end of the series of angularlyrelated passages to communicate the ignition chamber with an explosionchamber of an engine, an electrode carried by the body and having aplurality of spaced portions with their free ends defining an opening,an electrode extending through the opening and spaced from the ends ofthe portions of said first electrode to provide a series of spark gapsbetween said electrodes, a metallic sleeve carried by the insulator andhaving one end in communication with the atmosphere and its opposite endformed to provide a valve seat in the ignition chamber, a valve toengage said seat and having the second-named electrode detachablyconnected thereto, spring means between the tube and the valve to urgethe latter in engagement with the seat, and

the tube to the ignition chamber and for connecting an electricalconductor to the tube.

4. A spark plug comprising a body having one end closed, an insulatormounted in weasel opening, an electrode extending through the openingand spaced from the ends of the portions ot said mst electrode toAprovide a series oi' spark gaps between said electrodes, a metallicsleeve carried by the insulator and having one end in communication withthe atmosphere and its opposite end formed to provide a valve seat inthe ignition chamber, a valve to engage said seat and having thesecond-named electrode detachably connected thereto, spring meansbetween the tube and the valve to urge the latter in engagement with theseat, a cap adiustably secured to the tube for regulating the ilow ofair through the tube to the ignition ,chamber and for connecting anelectrical conductor to the tube, Vand a substantially cup-shaped;`insulating shield mounted onthe tube and against the insulator.

5. A spark plug comprising` a body having one end closed. an insulatorremovably mounted in said body and cooperating with the latter and theclosed end thereof in forming an ignition chamber, said closed end ofthe body having a series of spaced and radially extending passages and acentrally located passage, said p establishing communication between theignition chamber and an explosion chamber of an engine, a metallic tubecarried by the insulator and having a seat, a valve to engage the seat,an electrode carried by the valve,an electrode carried by the body,spring means between the valve and the tube to seat the valve, guidesbetween the valve and tube, said tube having ports, a cap having portsthreaded to the tube for establishing communication between theatmosphere and the igni- 1 tion chamber and capable of regulating thenow of air to the ignition chamber and to connect an electricalconductor to the t MARTIN OMARRA.

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